after a late night spent installing different Linux images (eventually settling on the latest Midori image) I was greatly surprised this morning when I discovered my USB Ethernet had magically started working. So I immediately SMB-mounted my server's MP3 storage (which I also use for my AudioTron and Rio Receiver) and started playing MP3s over the network using XMMS.
The built-in speaker sounded pretty much as I would have expected, i.e. not great. When plugged in some decent-quality headphones it became immediately clear that the circuit was not made to drive headphones, as the output level had to be maxed out to get decent output level, and severe distortion would occur at those output levels.
I got better results when I connected powered speakers; I experimented with the Sound Configuration page on the Midori configuration interface and found I could get acceptable output by setting Volume=100, PCM=50; I played with the Treble and Bass controls and could not discern any effect from changing them.
I'd like to hear what experience others have had with the audio output quality from their IA-1 units...